Projectile



Sept. 14, 1937.

1'. G EITMANN PHOJECTILE Filed Nov. 1a, 193e g .50km-v6 @4R65 ,u ///f////////L .Zamw/V6 @wmf .Tr/venian' @/w, mw, c?? ,M7 ifm-m Patented Sept.14, 1937 UNITED STATES PATET GFFICE signor to Westfalisch-AnhaltischeSprengstoff- Acten-Gesellschaft Chemische Fabriken, Berlin, Germany, aDeutsche Waffen- German company, and und Munitionsfabriken,

A. G., Berlin-Charlottenburg, Germany, a German company ApplicationNovember 18, 1936, Serial No. 111,474 In Germany December 30, 1935 8Claims.

Tracer shells are already known wherein the bursting charge is. causedto ignite by a tracer charge. In some cases, in these projectiles ofknown kind, a direct communication by means of passages or the like isprovided between the tracer charge and the bursting charge to allow theflame of the tracer charge to pass directly to the bursting charge.

In other known projectiles a metallic heatconducting member is insertedbetween the tracer charge and the charge of the shell in such a mannerthat flame cannot pass directly from the one charge to the other. Thetransmission of the heat of combustion of the tracer charge to ahighexplosive, shock-sensitive priming charge inserted adjacent themetallic heat-transmitting member effects the ignition of the burstingcharge.

The first-mentioned kind has the disadvantage that if the combustion ofthe tracer charge does not proceed regularly or, owing to other causes,ignition of the bursting charge may take place prematurely i. e. in somecases even in the gun-barrel, resulting in very serious disadvantages.

The second group presents the disadvantage that the transmitting orintermediate charges known heretofore for this purpose have beenfulminating compositions i. e. priming compositions that are sensitiveto friction and shock. Such substances, however, are additional sourcesof danger during the making of the shells, during the handling thereofand sometimes also when they are being red. 4

The object of the invention is to obviate lthe disadvantages of theknown construction and this is attained, in the case of a shell withignition of the bursting charge by the burning tracer charge, the heatof combustion whereof is transmitted to the charge of the shell, bymeans of a. metallic heat-conducting member, the heat-conducting membergiving olf its heat to a priming agent which, contrary tothe knowntransmitting means, is insensitive to friction and shock. Suchsubstances are for example nitrocellulose powder, nitroglycerine powder,black powder or other mixtures of oxygen carriers with combustiblematerials.

- This priming substance which is placed next to the metallicheat-conducting member, may be of such nature and quantity as also tobring about the disintegration of the actual charge of the shell andthus cause the desired disruption of the projectile. It may, however, beso selected as regards natureand quantity as to produce by itself alonean effect which is suflicient feefthe-desrred disruption of theprojectile. VAOf course, all combinations or processes situate betweenth" two extremes are possible.

It is within the scope of the invention, if particularly insensitivepriming agents are employed, which are also ignitible only with thegreatest possible difilculty, to provide means for increasing the amountof heat transmitted by the metal member. According to the invention,this may be eiected by additionally intensifying the heating effect ofthe burning tracer charge, for example by forming the layer of tracercharge, situated next to the heat-transmitting metal member, of amixture that burns with a particularly powerful heating effect. Anothermethod of causing the priming charge to ignite easily is to make themetallic conducting member, between the tracer charge and the substancesto be ignited, very thin. The two means mentioned for ensuring theignition of the priming agent may also be combined.

Constructional embodiments of the invention are shown, by way ofexample, in the accompanying drawing.

In the drawing,

Figure 1 is a fragmentary longitudinal section through a projectileembodying the principles of my invention; and

Figure 2 is a similar view showing another embodiment of the invention.

In Figure 1, a indicates the body of the shell and b a cavity in thebase of the shell in which the tracer charge c is accommodated. Screwedin the intermediate base d is a screw-threaded cap e, which is made of amaterial which is a good conducto-r of heat, preferably metal. The csp econtains a charge f which can be ignited by the heat transmitted fromthe burningtracer charge through a wall of the cap e, but which consistsof a substance that is practically insensitive to shock and friction. Asstated above, it may, therefore, consist of nitrocellulose powder,nitroglycerine powder, or black powder.

In the constructional example according to Figure 2, a. again indicatesthe body of the shell into the open base of which there is screwed atracer-charge casing g. This casing again contains the tracer charge c,which in this case, in its part c' lying next to the heat-transrnittingmember h, consists of a material that burns with a particularlyconsiderable evolution of heat. Said casing g is screwed into a centralhole in "e shell body and carries a heat-transmitting member h. As maybe seen from the drawing,

the member h is tapered rearwardly, for instance conically. In theinterior, the transmitting member h has a suitable cavity, which in theconstructional example shown likewise tapers rearwardly. Accommodatedwithin the cavity is the priming charge z', which may be made of thesame substance as the priming charge ,f employed in the constructionalexample according to Figure 1. l0 It is an obvious requirement that themetallic heat-transmitting member shall have sufcient strength towithstand the pressure of the explosion of the propelling charge of thecartridge and the stresses otherwise occurring, such as for example, thepressure generated on forcing in the tracer charge. On the other hand, aparticularly good and rapid transmission of heat must be effected. Thisrequirement is satisfied according to the invention by making the wallof the metallic transmitting member not of uniform thickness but so asto taper towards the tracer charge or by weakening it locally at oneplace.

In the manner known per se, an auxiliary charge k may adjoin the primingcharge i and may further improve the igniting action, but said auxiliarycharge should likewise be practically insensitive to shock or friction.

The new projectile according to the invention satises all conditionsrequired of a projectile which can be constructed without danger, issafe to handle, and is absolutely reliable and safe in action.

I claim:

1. A shell comprising a bursting charge :md a tracer charge initiatingthe ignition of the bursting charge, an intermediate member separatingin a gas-tight manner the bursting charge from the tracer charge, and apriming charge, for the bursting charge, which receives heat from thesaid intermediate member and which comprises a substance which ispractically insensitive to shock, pressure and friction.

2. A shell comprising a bursting charge and a aoeases tracer chargeinitiating the ignition of the bursting charge, and an intermediatemember separating in a gas-tight manner the bursting charge from thetracer charge, said bursting charge, which receives heat from the saidintermediate 5 member comprising a substance which is practicallyinsensitive to shock, pressure and friction.

3. A shell comprising a bursting charge and a tracer charge initiatingthe ignition of the bursting charge, a metal intermediate member, sepamrating in a gas-tight manner the bursting charge from the tracer charge,and a priming charge, for the bursting charge, which receives heat fromthe said metal intermediate member and the active mass of which consistsof a substance which 15 is practically insensitive to shock, pressureand friction.

4. A shell comprising a bursting charge and a tracer charge initiatingthe ignition of the bursting charge, and a metal intermediate member 20separating in a gas-tight manner the bursting charge from the tracercharge, said bursting charge, which receives heat from the said metalintermediate member, having as its active mass a substance which ispractically insensitive to 25 shock, pressure and friction.

5. A shell as claimed in claim 1, wherein the part of the tracer chargesituated next to the heat-transmitting member consists of material whichburns with a considerable evolution of heat. $0

6. A shell as claimed in claim 2, wherein the part of the tracer chargesituated next to the heat-transmitting member consists of material whichburns with a considerable evolution of heat.

7. A shell as claimed in claim 1, wherein the g5 heat-transmittingmember is made particularly thin between the tracer charge andthepriming charge, for example by being locally weakened.

. 8. A shell as claimed in claim 2, wherein the heat-transmitting memberis made particularly 40 thin between the tracer charge and the burstingcharge, for example by being locally weakened.

THEODOR GEI'I'MANN.

